Effect of bile pigments on the compromised gut barrier function in a rat model of bile duct ligation.

BACKGROUND: Studies have shown that the absence of bile in the gut lumen, either by bile duct ligation or bile diversion, induces mucosal injury. However, the mechanism remains elusive. In this study, the role of bile pigments in gut barrier function was investigated in a rat model of bile duct ligation. METHODS: Male Sprague Dawley (SD) rats were used in this study. After ligation of bile duct, the animals were administrated with free bilirubin, bilirubin ditaurate, or biliverdin by intragastric gavage. 1, 2, or 3 days later, the animals were sacrificed and the damage of mucosa was assessed by histological staining as well as biochemical parameters such as changes of diamine oxidase (DAO) and D-lactate (D-Lac) in the blood. Trypsin and chymotrypsin of the gut were also measured to determine how these digestive proteases may relate to the observed effects of bile pigments. RESULTS: Bile duct ligation (BDL) caused significant increases in gut trypsin and chymotrypsin along with damage of the mucosa as demonstrated by the histological findings under microscope, the reduced expression of tight junction molecules like occludin, and significant changes in DAO and D-lac in the blood. Free bilirubin but not bilirubin ditaurate or biliverdin showed significant inhibitions on trypsin and chymotrypsin as well as alleviated changes of histological and biochemical parameters related to gut barrier disruption. CONCLUSION: Bile may protect the gut from damage through inhibiting digestive proteases like trypsin and chymotrypsin by free bilirubin

Exploitation mode oriented heavy oil-oil sand recoverable reserves calculation methods

Based on special exploitation mode of heavy oil-oil sand, this paper established a recoverable reserves calculation method for heavy oil-oil sand. First, calculate recoverable reserves of single exploitation mode according to oil layer selection criterion including four parameters of buried depth, single layer thickness, porosity and oil saturation for different exploitation models. Second, calculate recoverable reserves for different exploitation model combination and the max recoverable reserves of the block; Last, set up heavy oil-oil sand recoverable reserves database. The method has great correlation with PRMS reserves evaluation system. The method has been used in the heavy oil classification evaluation for larger M of the J block in Venezuela heavy oil belt, the recoverable reserves are 4.06×108 t, 15.23×108 t and 7.40×108 t respectively by cold production, steam drive and steam-assisted gravity drainage, and the max recoverable reserves are 15.97×108 t, which provides reserves basement for block development. Key words: heavy oil, oil sand, reserves classification, exploitation mode, recoverable reserve

Evaporative and Wicking Functionalities at Hot Airflows of Laser Nano-/Microstructured Ti-6Al-4V Material

A novel multifunctional material with efficient wicking and evaporative functionalities was fabricated using hierarchical surface nano-/microstructuring by femtosecond laser micromachining. The created material exhibits excellent multifunctional performance. Our experiments in a wind tunnel demonstrate its good wicking and evaporative functionalities under the conditions of high-temperature airflows. An important finding of this work is the significantly enhanced evaporation rate of the created material compared with the free water surface. The obtained results provide a platform for the practical implementation of Maisotsenko-cycle cooling technologies for substantially increasing efficiency in power generation, thermal management, and other evaporation-based technologies. The developed multifunctional material demonstrates long-lasting wicking and evaporative functionalities that are resistant to degradation under high-temperature airflows, indicating its suitability for practical applications

Evaluation method for cluster platform controlling traps exploration: Taking the X block in Oriente basin, Ecuador as example

Abstract: Aimed at the small size, large quantity of traps and high environmental requirements of resource countries on slope belt of South America foreland basins, a new evaluation method is proposed for trap exploration on slope by taking the area controlled by a cluster platform as one evaluation unit. The evaluation process is: (1) trap geological risk analysis: including key oil & gas accumulation element analysis such as source, reservoir, seal, trap, migration and preservation; (2) trap resources calculation: including trap resources calculated with volumetric method, trap accumulation probability evaluation by geological risk analysis, and finally the risk trap resources by multiplying the above two values; (3) platform and drilling target selection: count the total risk trap resources and average risk trap resource of different platform and rank the drilling platforms according to the calculated resources; and rank the trap drilling sequence according to the risk trap resources. The method was used in ranking undrilled traps in the M1 layer of Block X, Oriente Basin, and the platform construction and trap drilling order was recommended accordingly which shows good results in practice. Key words: foreland basin, slope, trap evaluation, Oriente Basin, cluster platform, evaluation metho

Spatiotemporal dynamics of water film confinement during spreading and evaporation in highly hierarchical wicking nano/microstructure on Si surface at 120 °C

Enhancing the wicking/evaporative functionality of materials by surface nano/microstructuring is a key approach in creating advanced technologies based on the liquid–vapor phase change, particularly in the field of power generation for substantial fuel savings and reducing global greenhouse gas pollution. Despite the technological importance, the capillary flow of a liquid undergoing intensive evaporation on a hot nano/microstructured surface is not well understood. During the capillary flow on a nano/microstructured surface, water confinement undergoes a dramatical spatiotemporal change. The evaporation mechanisms of water confined in capillary nano/microstructures fundamentally depend on the scale of liquid confinement, making the dynamics of water confinement one of the basic characteristics in spreading/evaporation behavior of water on a hot capillary surface. Here, we develop an experimental technique for studying the water film confinement dynamics based on different optical footprints of nanoscale and microscale water confinements found in our work. We study both water film confinement dynamics and traditional capillary flow/receding dynamics of a water drop in a highly hierarchical capillary surface nano/microstructure created in our work using femtosecond laser processing. For the first time, we obtain the spatiotemporal map of water nano/microstructural confinements that provides basic data for the identification of evaporation mechanisms. The obtained results give important guidelines for engineering advanced materials with an efficient wicking/evaporative functionality

Markers and the histopathologic changes of gut barrier disruption.

<p>After BDL, the serum concentrations of DAO (A) and D-Lac (B) were assayed by spectrophotometric assay. Protein expression of occludin (65 kDa) was analyzed by Western blot (C). Occludin bands were normalized by actin and expressed as relative to control (D). Intestinal slices were stained with HE staining and analyzed by inverted fluorescence microscope, middle small intestine were blindly assessed for the degree of histopathology (E), all photos were captured at ×40 magnification (F). Results are mean ± SD from at least three independent experiments. ***<i>p</i><0.001 vs. respective control.</p

Linear-regression analysis of digestive proteases and the markers of gut barrier disruption over the course of 72 h.

<p>Linear-regression analysis of digestive proteases and the markers of gut barrier disruption over the course of 72 h.</p